From: Gordon K. <go...@gu...> - 2005-02-17 17:55:24
|
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta content="text/html;charset=windows-1252" http-equiv="Content-Type"> </head> <body bgcolor="#ffffff" text="#000000"> <tt>Proposed Robostix™ Features v0.1 (Gumstix Internal)<br> <br> 1. Controller: ATmega128<br> </tt> <blockquote><tt>a. Exposes:</tt><br> <blockquote><tt>i. 8 PWM Channels (2x8 bit, 6 programmable)</tt><br> <tt>ii. 6 A/D</tt><br> <tt>iii. 8 GPIO</tt><br> <tt>iv. 2 UART at logic levels</tt><br> <tt>v. JTAG</tt><br> </blockquote> <tt>b. 5V logic</tt><br> <tt>c. Gumstix communications</tt><br> <blockquote><tt>i. Gumstix (NSSP Port AND GPIO Select) <---> ATmega SPI</tt><br> <tt>ii. Gumstix (GPIO Reset Line AND GPIO Select)</tt><tt> <---> ATmega nReset</tt></blockquote> </blockquote> <tt>2. Connectors<br> </tt> <blockquote><tt>a. Peripherals are 1.25mm pitch</tt><br> <blockquote><tt>i. 24 Pair-wise over&under connectors</tt><tt> (over=signal/under=ground)</tt><br> <tt>ii. UART/JTAG/I2C sid-by-sides</tt><br> </blockquote> <tt>b. Gumstix stackable</tt><br> <blockquote><tt>i. Hirose 60 pin for motherboard</tt><br> <tt>ii. Hirose 60 pin for additional robostix (Optional)</tt><br> </blockquote> <tt>c. Mounting holes</tt><br> </blockquote> <tt>3. Power supply<br> </tt> <blockquote><tt>a. Sits on gumstix v_batt bus</tt><br> <tt>b. v_batt /ground exposed on separate connectors</tt><br> </blockquote> <tt>4. Form factor<br> </tt> <blockquote><tt>a. 80 mm x 25.4 mm</tt><br> <tt>b. 3 mm interboard distance</tt></blockquote> </body> </html> |
From: Dave H. <dhy...@gm...> - 2005-02-17 18:40:20
|
Drool, droool. It would also be extremely useful to bring out the ISP pins that could be used for programming the ATMega128. There is a standard 2x5 and 2x3 layout using 0.1", but I don't see any problems just bringing the signals out (and having to make a custom cable). I have an AVRISP (available from Digikey for $29) that I use for programming my ATMega parts. It needs +5, GND, MOSI, MISO, SCK, and an optional line (typically connected to an LED and one of the pins on the ATMega. You're suggesting using the SPI to connect to the gumstix. Since these are also used for programming are you proposing that you'll be providing some type of programming for the ATMega from the gumstix side? Even if you leave the SPI stuff the way it is, if you bring the ISP signals out to a connector, then the ATMega could be programmed using the ISP when its not connected to the gumstix. I normally only do this once, to download a bootloader and then use the bootloader from that point on to download code (which could use a serial port, or the i2c bus, etc). Under exposes, you didn't mention i2c. I think it would be useful to have the gumstix i2c and the ATMega i2c both exposed, and perhaps have some jumpers so that thay could be connected together (with appropriate voltage translation). That way you could use the i2c bus to communicate with the ATMega, or you could use the two i2c busses independantly. Obviously, if you're going to allow multiple robostix to be stacked, then you'd need a way of jumpering which robostix responds to which chip select. Another clever way to do this would be to have a set of chip select pins that get shifted over by one as each robostix gets stacked up. That way the first robostix is always CS0 and the 2nd one is always CS2 (no jumpering required). Connector to gumstix has CS0-in, CS1-in, CS2-in, CS3-in CS0-in goes to the chip select for this board. CS1-in from the top connector goes to CS0-out on the bottom. CS2-in from the top connector goes to CS1-out on the bottom. CS3-in from the top connector goes to CS2-out on the bottom. scale to suit the max number of robotstix you want to support. You could also support 4 boards using 2 lines by having jumpers and a little decoder on each board. You didn't mention anything about the crystal for the Meag128 (it can use an internal one or have an external one). Personally, I'd prefer an external one (less drift for using the UARTs and other timing). Dave Hylands On Thu, 17 Feb 2005 09:54:33 -0800, Gordon Kruberg <go...@gu...> wro= te: > Proposed Robostix=E2=84=A2 Features v0.1 (Gumstix Internal) > =20 > 1. Controller: ATmega128 > =20 > a. Exposes: > =20 > i. 8 PWM Channels (2x8 bit, 6 programmable) > ii. 6 A/D > iii. 8 GPIO > iv. 2 UART at logic levels > v. JTAG > b. 5V logic > c. Gumstix communications > =20 > i. Gumstix (NSSP Port AND GPIO Select) <---> ATmega SPI > ii. Gumstix (GPIO Reset Line AND GPIO Select) <---> ATmega nReset 2. > Connectors > =20 > a. Peripherals are 1.25mm pitch > =20 > i. 24 Pair-wise over&under connectors (over=3Dsignal/under=3Dground) > ii. UART/JTAG/I2C sid-by-sides > b. Gumstix stackable > =20 > i. Hirose 60 pin for motherboard > ii. Hirose 60 pin for additional robostix (Optional) > c. Mounting holes > 3. Power supply > =20 > a. Sits on gumstix v_batt bus > b. v_batt /ground exposed on separate connectors > 4. Form factor > =20 > a. 80 mm x 25.4 mm > b. 3 mm interboard distance > ------------------------------------------------------- SF email is > sponsored by - The IT Product Guide Read honest & candid reviews on hundr= eds > of IT Products from real users. Discover which products truly live up to = the > hype. Start reading now. > http://ads.osdn.com/?ad_id=3D6595&alloc_id=3D14396&op=3Dclick > _______________________________________________ gumstix-users mailing lis= t > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users |
From: Dave H. <dhy...@gm...> - 2005-02-17 18:41:31
|
> It needs +5, GND, MOSI, MISO, SCK, and an optional line (typically > connected to an LED and one of the pins on the ATMega. Oops - it needs reset too. -- Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ |
From: Dave H. <dhy...@gm...> - 2005-02-17 22:04:04
|
> i. Gumstix (NSSP Port AND GPIO Select) <---> ATmega SPI > ii. Gumstix (GPIO Reset Line AND GPIO Select) <---> ATmega nReset 2. On further investigation, it looks like AVRDUDE (http://www.bsdhome.com/avrdude/) should be able to work (perhaps with a mod or two) to program the ATMega128 directly from the gumstix. -- Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ |
From: mark g. <mar...@th...> - 2005-02-18 14:55:08
|
On Thu, 2005-02-17 at 09:54 -0800, Gordon Kruberg wrote: > Proposed Robostix=99 Features v0.1 (Gumstix Internal) >=20 > 1. Controller: ATmega128 > a. Exposes: > i. 8 PWM Channels (2x8 bit, 6 programmable) > ii. 6 A/D > iii. 8 GPIO > iv. 2 UART at logic levels > v. JTAG > b. 5V logic > c. Gumstix communications > i. Gumstix (NSSP Port AND GPIO Select) <---> ATmega > SPI > ii. Gumstix (GPIO Reset Line AND GPIO Select)<---> > ATmega nReset I would like to have i2c between gumstix and Atmega as well. There is a large stack of I2C code already in Linux I can leverage, to convert over to SPI may or may not be a bit of work. Also, you want to inlcude a serial connection between the gumstix and the Atmega. We would want to load Atmega code via the gumstix. Lastly I think you need to be sure you have GPIO interrupt capablitity for the gumstix to signal the Atmega, and the Atmega to signal the gumstix. (I'm not sure if the above provides this) > 2. Connectors > a. Peripherals are 1.25mm pitch > i. 24 Pair-wise over&under connectors > (over=3Dsignal/under=3Dground) > ii. UART/JTAG/I2C sid-by-sides > b. Gumstix stackable > i. Hirose 60 pin for motherboard > ii. Hirose 60 pin for additional robostix (Optional) > c. Mounting holes > 3. Power supply > a. Sits on gumstix v_batt bus > b. v_batt /ground exposed on separate connectors Will I be able to drive >500mA of inferred sensors off the Atmega power supply? If not you need a bigger regulator. > 4. Form factor > a. 80 mm x 25.4 mm > b. 3 mm interboard distance Smaller may not be better in this case. Make sure the pitch is big enough to work with by folks with big hands, and make the board sturdy enough to be able to take a few soldering screw ups and still be recoverable. Some PCB's don't like it when I have to use my solder sucker. > ------------------------------------------------------- SF email is > sponsored by - The IT Product Guide Read honest & candid reviews on > hundreds of IT Products from real users. Discover which products truly > live up to the hype. Start reading now. http://ads.osdn.com/? > ad_id=3D6595&alloc_id=3D14396&op=3Dclick > _______________________________________________ gumstix-users mailing > list gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users |
From: Dave H. <dhy...@gm...> - 2005-02-18 15:48:08
|
> Will I be able to drive >500mA of inferred sensors off the Atmega power > supply? If not you need a bigger regulator. Actually, this brings up a very good point. I'd like to see the ability (perhaps it involves cutting some traces) to easily replace/override the on-board voltage regulator with an off-board one. This may just involve running the traces in a manner that makes them easily accessible. I'm planning on using a switcher (LM267x series) so that I get better battery life (and have a 12v battery brought down to 5v (or 3.3v) without wasting so much. So, if the board includes a linear regulator, then I'll want to bypass it. If your sensors draw more current than the on-board regulator can deliver, then you can easily provide your own external power regulator. In the fire fighting bots (i.e. at Trinity) many people put a separate regulator for each GP2D12 (IR sensor) to provide the necessary current and to isolate the noise that they generate on the power rails. > > 4. Form factor > > a. 80 mm x 25.4 mm > > b. 3 mm interboard distance > > Smaller may not be better in this case. Make sure the pitch is big > enough to work with by folks with big hands, and make the board sturdy > enough to be able to take a few soldering screw ups and still be > recoverable. Some PCB's don't like it when I have to use my solder > sucker. Yeah. The 0.050" (essentially same as 1.25mm) pitch isn't too bad. That's what's on the MegaBitty (which is a 1" square board). You can see some pictures here: <http://www.junun.org/MarkIII/Info.jsp?item=49#> <http://www.davehylands.com/Robotics/Phantom/Small/03-Phantom-Electronics.html> <http://www.davehylands.com/Robotics/Phantom/Small/04-Phantom-Mega-Bitty.html> <http://www.davehylands.com/Robotics/Stinger/Small/06-Electronics.html> Making cables for the 1.25mm is a pain though, becasue there aren't any cost effective crimpers available (the hirose ones are something ridiculous like $1000). In the megabitty pictures, I just used ordinary headers and soldered wires individually to the headers and used heat shrink for added strength. Those black things that run across the top of Stinger are GP2D12's (for those on the list who aren't familiar with that particular sensor). > i. 24 Pair-wise over&under connectors (over=signal/under=ground) What does the over/under bit mean? Are you talking about over/under the board? Or do you just mean there will be a 2xN connector? -- Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ |